TL598 PULSE-WIDTH-MODULATION CONTROL CIRCUITS

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1 Complete PWM Power Control Function Totem-Pole Outputs for 200-mA Sink or Source Current Output Control Selects Parallel or Push-Pull Operation Internal Circuitry Prohibits Double Pulse at Either Output ariable Dead-Time Provides Control Over Total Range Internal Regulator Provides a Stable 5- Reference Supply, Trimmed to 1% Tolerance On-Board Output Current-Limiting Protection Undervoltage Lockout for Low CC Conditions Separate Power and Signal Grounds TL598Q Has Extended Temperature Range C to 125 C ERROR 1IN+ AMP 1 1IN FEEDBACK DTC CT RT SIGNAL GND OUT1 D OR N PACKAGE (TOP IEW) IN+ ERROR 2IN AMP 2 REF OUTPUT CTRL CC C POWER GND OUT2 description The TL598 incorporates all the functions required in the construction of pulse-width-modulated (PWM) controlled systems on a single chip. Designed primarily for power-supply control, the TL598 provides the systems engineer with the flexibility to tailor the power-supply control circuits to a specific application. The TL598 contains two error amplifiers, an internal oscillator (externally adjustable), a dead-time control (DTC) comparator, a pulse-steering flip-flop, a 5- precision reference, undervoltage lockout control, and output control circuits. Two totem-pole outputs provide exceptional rise- and fall-time performance for power FET control. The outputs share a common source supply and common power ground terminals, which allow system designers to eliminate errors caused by high current-induced voltage drops and common-mode noise. The error amplifier has a common-mode voltage range from 0 to CC 2. The DTC comparator has a fixed offset that prevents overlap of the outputs during push-pull operation. A synchronous multiple supply operation can be achieved by connecting RT to the reference output and providing a sawtooth input to CT. The TL598 device provides an output control function to select either push-pull or parallel operation. Circuit architecture prevents either output from being pulsed twice during push-pull operation. The output frequency for push-pull applications is one-half the oscillator frequency.f O f O 1 RT CT. 1.. For single-ended applications: 2RTCT The TL598C is characterized for operation from 0 C to 70 C. The TL598Q is characterized for operation from 40 C to 125 C. Please be aware that an important notice concerning availability, standard warranty, and use in critical applications of Texas Instruments semiconductor products and disclaimers thereto appears at the end of this data sheet. PRODUCTION DATA information is current as of publication date. Products conform to specifications per the terms of Texas Instruments standard warranty. Production processing does not necessarily include testing of all parameters. Copyright 1999, Texas Instruments Incorporated POST OFFICE BOX DALLAS, TEXAS

2 FUNCTION TABLE INPUT/OUTPUT CTRL OUTPUT FUNCTION I = GND Single-ended or parallel output I = REF Normal push-pull operation TA AAILABLE OPTIONS PACKAGED DEICES SMALL OUTLINE (D) PLASTIC DIP (N) 0 C to 70 C TL598CD TL598CN 40 C to 125 C TL598QD Chip forms are tested at 25 C. CHIP FORM (Y) functional block diagram RT CT DTC Oscillator DTC Comparator OUTPUT CTRL (see Function Table) 13 1D C1 11 C 8 OUT1 1IN+ 1IN 2IN+ 2IN FEEDBACK Error Amplifier + 1 Error Amplifier + 2 PWM Comparator Reference Regulator Pulse-Steering Flip-Flop Undervoltage Lockout Control 9 OUT2 10 POWER GND 12 CC 14 7 REF SIGNAL GND 0.7 ma 2 POST OFFICE BOX DALLAS, TEXAS 75265

3 absolute maximum ratings over operating free-air temperature range (unless otherwise noted) Supply voltage, CC (see Note 1) Amplifier input voltage, I CC Collector voltage Output current (each output), sink or source, I O ma Package thermal impedance, θ JA (see Notes 2 and 3): D package C/W N package C/W Lead temperature 1,6 mm (1/16 inch) from case for 10 seconds C Storage temperature range, T stg C to 150 C Stresses beyond those listed under absolute maximum ratings may cause permanent damage to the device. These are stress ratings only, and functional operation of the device at these or any other conditions beyond those indicated under recommended operating conditions is not implied. Exposure to absolute-maximum-rated conditions for extended periods may affect device reliability. NOTES: 1. All voltage values, except differential voltages, are with respect to the signal ground terminal. 2. Maximum power dissipation is a function of TJ(max), θ JA, and TA. The maximum allowable power dissipation at any allowable ambient temperature is PD = (TJ(max) TA)/θ JA. Operating at the absolute maximum TJ of 150 C can impact reliability. 3. The package thermal impedance is calculated in accordance with JESD 51, except for through-hole packages, which use a trace length of zero. recommended operating conditions MIN MAX Supply voltage, CC 7 40 Amplifier input voltage, I 0 CC 2 Collector voltage 40 Output current (each output), sink or source, IO 200 ma Current into feedback terminal, IIL 0.3 ma Timing capacitor, CT µf Timing resistor, RT kω Oscillator frequency, fosc khz Operating free-air temperature, TA TL598C 0 70 TL598Q C POST OFFICE BOX DALLAS, TEXAS

4 electrical characteristics over recommended operating free-air temperature range, CC = 15 (unless otherwise noted) reference section (see Note 4) Output voltage (REF) IO = 1 ma TL598C TL598Q MIN TYP MAX MIN TYP MAX TA = 25 C TA = full range Input regulation CC = 7 to 40 TA = 25 C m Output regulation Output voltage change with temperature IO =1mAto10mA 10 TA = 25 C TA = full range TA = MIN to MAX m/ Short-circuit output current REF = ma Full range is 0 C to 70 C for the TL598C, and 40 C to 125 C for the TL598Q. All typical values except for parameter changes with temperature are at TA = 25 C. Duration of the short circuit should not exceed one second. NOTE 4: Pulse-testing techniques that maintain the junction temperature as close to the ambient temperature as possible must be used. oscillator section, C T = µf, R T = 12 kω (see Figure 1) (see Note 4) MIN TYP MAX Frequency 100 khz Standard deviation of frequency All values of CC, CT, RT, TA constant 100 Hz/kHz Frequency change with voltage CC = 7 to 40, TA = 25 C 1 10 Hz/kHz TA = full range Frequency change with temperature# TA = full range, CT = 0.01 µf Hz/kHz 2 Full range is 0 C to 70 C for the TL598C, and 40 C to 125 C for the TL598Q. All typical values except for parameter changes with temperature are at TA = 25 C. 4 N. xn X. 2 Standard deviation is a measure of the statistical distribution about the mean as derived from the formula: n1 N 1 # Effects of temperature on external RT and CT are not taken into account. error amplifier section (see Note 4) MIN TYP MAX Input offset voltage FEEDBACK = m Input offset current FEEDBACK = na Input bias current FEEDBACK = µa Common-mode input voltage range CC = 7 to 40 0 to CC 2 Open-loop voltage amplification O (FEEDBACK) = 3, O (FEEDBACK) = 0.5 to db Unity-gain bandwidth 800 khz Common-mode rejection ratio CC = 40, IC = 6.5, TA = 25 C db Output sink current (FEEDBACK) FEEDBACK = ma Output source current (FEEDBACK) FEEDBACK = ma Phase margin at unity gain FEEDBACK = 0.5 to 3.5, RL = 2 kω 65 Supply-voltage rejection ratio FEEDBACK = 2.5, CC = 33, RL = 2 kω 100 db All typical values except for parameter changes with temperature are at TA = 25 C. m 4 POST OFFICE BOX DALLAS, TEXAS 75265

5 electrical characteristics over recommended operating free-air temperature range, CC =15 (unless otherwise noted) undervoltage lockout section (see Note 4) Threshold voltage Hysteresis TL598C TL598Q MIN MAX MIN MAX TA = 25 C TA = full range TA = 25 C TA = full range Full range is 0 C to 70 C for the TL598C, and 40 C to 125 C for the TL598Q. Hysteresis is the difference between the positive-going input threshold voltage and the negative-going input threshold voltage. NOTE 4. Pulse-testing techniques must be used that maintain the junction temperature as close to the ambient temperature as possible. output section (see Note 4) CC = 15, IO = 200 ma 12 High-level output voltage C = 15 IO = 20 ma 13 CC = 15, IO = 200 ma 2 Low-level output voltage C = 15 IO = 20 ma 0.4 Output-control input current NOTE 4. MIN MAX m I I = ref 3.5 ma I = µa Pulse-testing techniques must be used that maintain the junction temperature as close to the ambient temperature as possible. dead-time control section (see Figure 1) (see Note 4) TL598C TL598Q MIN TYP MAX MIN TYP MAX Input bias current (DTC) I = 0 to µa Maximum duty cycle, each output DTC = Zero duty cycle Input threshold voltage (DTC) Maximum duty cycle 0 0 All typical values except for parameter changes with temperature are at TA = 25 C. NOTE 4. Pulse-testing techniques must be used that maintain the junction temperature as close to the ambient temperature as possible. pwm comparator section (see Note 4) MIN TYP MAX Input threshold voltage (FEEDBACK) DTC = Input sink current (FEEDBACK) (FEEDBACK) = ma All typical values except for parameter changes with temperature are at TA = 25 C. NOTE Pulse-testing techniques must be used that maintain the junction temperature as close to the ambient temperature as possible. total device (see Figure 1) (see Note 4) Standby supply current MIN TYP MAX RT = ref, CC = All other inputs and outputs open CC = Average supply current DTC = 2 15 ma All typical values except for parameter changes with temperature are at TA = 25 C. NOTE 4. Pulse-testing techniques must be used that maintain the junction temperature as close to the ambient temperature as possible. ma POST OFFICE BOX DALLAS, TEXAS

6 electrical characteristics over recommended operating free-air temperature range, CC = 15 (unless otherwise noted) switching characteristics, T A = 25 C (see Note 4) Output-voltage rise time CL = 1500 pf, C = 15, CC = 15, ns Output-voltage fall time See Figure NOTE 4. Pulse-testing techniques must be used that maintain the junction temperature as close to the ambient temperature as possible. electrical characteristics, CC = 15, T A = 25 C reference section (see Note 4) MIN TYP MAX Output voltage (REF) IO = 1 ma 5 Input regulation CC = 7 to 40 2 m Output regulation IO = 1 ma to 10 ma 1 m Output-voltage change with temperature 2 m/ Short-circuit output current REF = 0 48 ma All typical values except for parameter changes with temperature are at TA = 25 C. Duration of the short circuit should not exceed one second. oscillator section, C T = µf, R T = 12 kω (see Figure 1) (see Note 4) Frequency 100 khz Standard deviation of frequency All values of CC, CT, RT, TA constant 100 Hz/kHz Frequency change with voltage CC = 7 to 40, 1 Hz/kHz Standard deviation is a measure of the statistical distribution about the mean as derived from the formula: 24 N. xn X. 2 n1 N 1 NOTE 4. Pulse-testing techniques that maintain the junction temperature as close to the ambient temperature as possible must be used. error amplifier section (see Note 4) Input offset voltage Feedback = m Input offset current Feedback = na Input bias current Feedback = µa Open-loop voltage amplification O (FEEDBACK) = 3, O (FEEDBACK) = 0.5 to db Unity-gain bandwidth 800 khz Common-mode rejection ratio CC = 40, IC = 6.5, 80 db Output sink current (FEEDBACK) FEEDBACK = ma Phase margin at unity gain FEEDBACK = 0.5 to 3.5, RL = 2 kω 65 Supply-voltage rejection ratio FEEDBACK = 2.5, CC = 33, RL = 2 kω 100 db NOTE 4. Pulse-testing techniques that maintain the junction temperature as close to the ambient temperature as possible must be used. 6 POST OFFICE BOX DALLAS, TEXAS 75265

7 electrical characteristics, CC = 15, T A = 25 C dead-time control section (see Figure 1) (see Note 4) Input bias current (DTC) I = 0 to µa Input threshold voltage (DTC) Zero duty cycle 3 pwm comparator section (see Note 4) Input threshold voltage (FEEDBACK) DTC = Input sink current (FEEDBACK) FEEDBACK = ma total device (see Figure 1) (see Note 4) Standby supply current RT = ref, CC = All other inputs and outputs open CC = ma Average supply current DTC = 2 15 ma POST OFFICE BOX DALLAS, TEXAS

8 MEASUREMENT INFORMATION Output C 1 2 IN+ IN ERROR AMP 1 CC ERROR AMP 2 IN+ IN µf Test Inputs 12 kω FEEDBACK DTC CT RT SIGNAL GND REF OUTPUT CTRL C OUT1 OUT2 POWER GND kω 15 OUTPUT 1 OUTPUT 2 I OUTPUT CONFIGURATION + REF POWER GND FEEDBACK MAIN DEICE TEST CIRCUIT + ERROR AMPLIFIER TEST CIRCUIT Figure 1. Test Circuits C 90% 90% Output CL = 1500 pf 10% 10% 0 POWER GND tr tf OUTPUT CONFIGURATION OUTPUT OLTAGE WAEFORM Figure 2. Switching Output Configuration and oltage Waveform 8 POST OFFICE BOX DALLAS, TEXAS 75265

9 TYPICAL CHARACTERISTICS fosc Oscillator Frequency Hz 100 k 40 k 10 k 4 k 1 k % OSCILLATOR FREQUENCY AND FREQUENCY ARIATION vs TIMING RESISTANCE 1% CT = 1 µf 0% 0.1 µf 0.01 µf CC = µf f = 1% Amplifier oltage Amplification db AMPLIFIER OLTAGE AMPLIFICATION vs FREQUENCY CC = 15 O = 3 TA = 25 C 10 1 k 4 k 10 k 40 k 100 k 400 k 1 M RT Timing Resistance Ω Frequency variation ( f) is the change in predicted oscillator frequency that occurs over the full temperature range. 0 1 k 10 k 100 k 1 M f Frequency Hz Figure 4 Figure 3 POST OFFICE BOX DALLAS, TEXAS

10 IMPORTANT NOTICE Texas Instruments and its subsidiaries (TI) reserve the right to make changes to their products or to discontinue any product or service without notice, and advise customers to obtain the latest version of relevant information to verify, before placing orders, that information being relied on is current and complete. All products are sold subject to the terms and conditions of sale supplied at the time of order acknowledgement, including those pertaining to warranty, patent infringement, and limitation of liability. TI warrants performance of its semiconductor products to the specifications applicable at the time of sale in accordance with TI s standard warranty. Testing and other quality control techniques are utilized to the extent TI deems necessary to support this warranty. Specific testing of all parameters of each device is not necessarily performed, except those mandated by government requirements. CERTAIN APPLICATIONS USING SEMICONDUCTOR PRODUCTS MAY INOLE POTENTIAL RISKS OF DEATH, PERSONAL INJURY, OR SEERE PROPERTY OR ENIRONMENTAL DAMAGE ( CRITICAL APPLICATIONS ). TI SEMICONDUCTOR PRODUCTS ARE NOT DESIGNED, AUTHORIZED, OR WARRANTED TO BE SUITABLE FOR USE IN LIFE-SUPPORT DEICES OR SYSTEMS OR OTHER CRITICAL APPLICATIONS. INCLUSION OF TI PRODUCTS IN SUCH APPLICATIONS IS UNDERSTOOD TO BE FULLY AT THE CUSTOMER S RISK. In order to minimize risks associated with the customer s applications, adequate design and operating safeguards must be provided by the customer to minimize inherent or procedural hazards. TI assumes no liability for applications assistance or customer product design. TI does not warrant or represent that any license, either express or implied, is granted under any patent right, copyright, mask work right, or other intellectual property right of TI covering or relating to any combination, machine, or process in which such semiconductor products or services might be or are used. TI s publication of information regarding any third party s products or services does not constitute TI s approval, warranty or endorsement thereof. Copyright 1999, Texas Instruments Incorporated

TL594 PULSE-WIDTH-MODULATION CONTROL CIRCUITS

TL594 PULSE-WIDTH-MODULATION CONTROL CIRCUITS Complete PWM Power Control Circuitry Uncommitted Outputs for 200-mA Sink or Source Current Output Control Selects Single-Ended or Push-Pull Operation Internal Circuitry Prohibits Double Pulse at Either